Field of the Invention
The present invention relates to a negative pressure generator, and more particularly, to a negative pressure generator for providing a vacuum source to an oral interface device placed in an oral cavity of a patient with sleep breathing problem.
Prior Art
Obstructive sleep apnea (OSA), hypopnea, and upper airway resistance syndrome (UARS) are among a variety of known disorders characterized by episodes of complete or partial upper airway blockage during sleep, anesthetization, or post anesthesia. OSA, hypopnea, and UARS cause intermittent interruption of breathing during sleep with the consequence of potentially severe oxyhemoglobin desaturation. Typically, those afflicted with OSA, hypopnea, and/or UARS experience repeated, frequent arousal from sleep in response to the oxygen deprivation. The arousals result in sleep fragmentation and poor sleep continuity.
The use of a Constant Positive Airway Pressure (CPAP) machine is the most common treatment for OSA patients among the current treatment option. The CPAP machine which consists of a mask, a pump and a humidifier continuously blows pressurized air into a patient's nose to keep his/her airway open during sleep. The CPAP machine is quite effective; however, it causes unpleasant side effects such as dry throat and nasal congestion. Patients who use the CPAP machine often have swollen nasal mucosa and experience headaches in the morning. The treatment with the CPAP machine has a low patient compliance because of its significant side effects.
Currently, an improved treatment of OSA involves applying a negative pressure to a forward end of a patient's oral cavity, typically at or just behind the lips so that the negative pressure will pull his/her tongue forward to lift the rear portion of the tongue away from the back of the airway. Various oral devices using oral negative pressure, such as the oral interface device disclosed in the PCT International Patent Application No. PCT/US14/11129 filed on Jan. 10, 2014, have been developed to facilitate breathing for those suffering from OSA, hypopnea, and/or UARS by properly controlling negative pressure applied to the oral cavity. Moreover, oral devices using oral negative pressure can use a negative pressure control system, such as an electronic pump disclosed in the U.S. Patent Publication No. 2009/0288660 or the like, to provide a vacuum source.